Abstract
Despite aerosol inhalation therapy plays a key role in the treatment of bronchial diseases, the devices for the treatment are not necessarily satisfactory. The present study was designed for the comparative functional assessment of our newly developed device with one of marketed devices, Spinhaler.
In order to evaluate them precisely and objectively, we assembled new two detection systems. One was for the detection of spouting amount, and another for pressure drop, or airway resistance. With regard to distribution of powder, we followed FDA requirement, using cascade impactor. Thus, we assessed these two devices from view points of these three functions, i. e. distribution, spouting and pressure drop, or airway resistance.
As the study results, the spouting and distribution functions of Spinhaler were found poor. The spouting amount of Spinhaler was unstable and varied from 0 % to 100 %, mostly 30 to 50 %. Sometimes its needle did not puncture the capsule at all. Spinhaler took one second at the fastest but usually took more than ten seconds to complete its spouting.
On the contrary, Jethaler spouted out always more than 90 % of the powder and completed spouting within 0.1 second. Collection of the most appropriate particle size for inhalation to bronchi, from 1.1 up to 7 micro meter, with Jethaler was larger by 30 to 50 % than that with Spinhaler. The application of unique control mechanism of air stream enabled us to develop this device for dry powder inhalation. This new device weighs only 30 grams and is handy.
